INTRODUCTION:

Herbal medicines in the simplest form are medicines or drugs made from herbs or plants and can be said to possess several synonyms all of which refer to plants as the raw materials for medicine namely: phytomedicines, plant medicines, green medicines, traditional medicine potions;

traditional remedies, plant drugs, forest health products among others¹.The World Health Organization ² also defined herbal medicine as finished labeled medicinal products that contain as active ingredients aerial or underground parts of plants or other plant materials or combinations thereof whether in the crude state or as plant preparations. Plant materials include juices, gums, fatty oils and any other substances of this nature. Herbal medicine may contain standard excipients in addition to the active ingredients. Medicines containing plant material combined with chemically defined active substances including chemically defined isolated constituents of plants are not considered to be herbal medicine. Exceptionally, in some countries herbal medicine may also contain by tradition, natural organic or inorganic active ingredients which are not of plant origin ². Herbal medicines are made from medicinal plants and specifically they could be obtained from tree barks, leaves, flowers, roots and stems. These may be dried and converted into powdery forms and mixed with certain foods as sauce in soups. They may also be incorporated into creams or soaps as adjuncts for external use or taken orally with fluid. They could be prepared in solid dosage forms too. Furthermore, these plant materials may be immersed in water, alcohol or in any suitable solvent in a closed vessel and allowed to stand for up to 7 days (maceration) or boiled over a specific period of time (decoction). At times, boiling water could be poured on a specific quantity of plant material and the mixture is allowed to stand for 10-15 minutes (infusion) in order to obtain the desired herbal medicine. Herbal medicines could be monocomponent or multicomponent in nature. Injectable forms of herbal medicine are not yet in existence for now in Nigeria ³.

Herbal medicines enjoy a wide degree of acceptability in developing countries because it is close to the culture of the people, cheap, readily available and probably considered not toxic in nature. High population of people living in developing countries rely heavily on herbal medicine for their healthcare needs in spite of the fact that questions have been raised on the issue of its regulation and standardization with regards to quality, safety and efficacy ⁴. However, Barnes ⁵ opined that the regulation for the sales, importation and the production of herbal medicines especially in developing nations is relaxed when compared to the degree of scrutiny for conventional western/allopathic medicines.

Some Nigerian universities and private research institutes have made some progress in herbal medicine research. For instance, early works in the University of Ife (now Obafemi Awolowo University) have shown that chewing sticks do kill oral micro flora and, are therefore effective in cleaning the mouth ⁶. The extract of Senna Podocarpa Guill.et Perr (Caesalpinaceae) pod (Asuwon ibile) used as purgative and worm expellant has been shown to be as good a laxative as commercial Senna ⁷.Ocimum gratisimum Linn. (Lamiaceae) (Efirin in Yoruba) oil calms overactive gut and thus cures diarrhea. It demonstrates considerable inhibitory activity against strains of enteroaggregative E. coli ⁸. In a private herbal institute, Pax Clinic and Research Laboratories in Ewu, Edo state, it has been shown that tomato, onion, bitter leaf and hibiscus flower are among the most potent herbs for the treatment of diabetes, hypertension and cancer. It has also been shown that lemon grass and cassia leaves are excellent for weight reduction ⁹. The unprecedented global upsurge of interest in herbal medicine is perhaps a measure of a more realistic perception of the limitations of orthodox medicines in terms of cost, accessibility, effectiveness and safety ⁴. Even in developed countries, resurgence of interest in herbal medicine has been due to the preference of many consumers for products of natural origin ¹⁰.

This study is aimed at assessing the generation and the level of acceptability of herbal medicines (R&D) outputs in Nigeria. This is with a view to understanding better the factors that influence their generation and determine the degree of acceptability of herbal medicine (R&D) outputs in Nigeria.

MATERIAL AND METHODS:

The study covered the major actors within the Nigerian Health Innovation System Environment (NHISE) where R&D activities in herbal medicines are carried out. Apart from herbal consumers, other major actors in the NHISE include the universities, research institutes and manufacturing pharmaceutical firms/herbal medicines producers. The reason for targeting these areas is that ¹¹ has emphasized that most of the radical innovations today are usually as a result of deliberate R&D activities in enterprises and/or in universities, government and research laboratories.

The study also covered 13 universities in Nigeria that were into pharmaceutical teaching and research, 3 research institutes and 50 manufacturing pharmaceutical firms/Herbal producers which were drawn from chemical and pharmaceutical sub-sectors. From the above sample population, a sample size of 100 herbal medicine scientists in the13 universities, 100 herbal medicine scientists in the 3 research institutes, 125 scientists in the 50 herbal medicine manufacturing firms was drawn. Opinions of these researchers were sort on the number of herbal medicines (R&D) outputs generated as well as the factors influencing such results from their various establishments. These establishments include thirteen Nigerian universities namely, Obafemi Awolowo, Lagos, Nigeria, Ahmadu Bello, Benin, Maiduguri, Jos, Ibadan, Port-Harcourt, Niger Delta, Madonna, Olabisi Onabanjo and Igbinedion. The three research institutes were, the National Institute for Pharmaceutical Research and Development (NIPRD), Nigerian Natural Medicine and Development Agency (NNMDA) and Pax Herbal Clinic. The 50 manufacturing pharmaceutical firms were located in the six geopolitical zones across the country. Furthermore, with the aid of six research assistance each from the six geopolitical zones namely, North East, North Central, North West, South West, South East and South-South, questionnaires were administered to 300 herbal medicine consumers whose opinions were sort on the acceptability of herbal medicines based on certain parameters such as herbal medicines affordability, availability, packaging, safety, efficacy, and side effects. This was backed by oral interview. Structured questionnaires were the main instrument used to collect information on the generation and degree of acceptability of herbal medicine R&D outputs from the respondents. The questionnaires had two components: classification questions and questions on core issues. The questions covering the implicated variables were structured, scaled, and mostly close-ended and presented in multiple-choice forms. The choice of any particular type of question was based on its appropriateness and power to elicit precise response to questions. The classification questions assisted in classifying the targeted institutions/organizations by age or sector of operation for the purpose of analysis. The questions on core issues for the herbal medicine R&D scientists had to do with the factors influencing the generation of herbal medicines R&D outputs. Questions were raised on the number of products developed and whether herbal medicine consumers did take herbal medications alongside orthodox medicines. Herbal consumers were then asked to assess the acceptability of herbal medicine R&D outputs on a 5-point “Likert Scale” based on the following parameters namely: availability, safety, side effects, affordability, efficacy and packaging. All research instruments; questionnaire and interview schedules were pre-tested in two universities that conduct pharmaceutical research, two public research institutes, four manufacturing pharmaceutical firms/herbal producers and thirty herbal medicine consumers. The results of the pre-tested questionnaire were used to make necessary modifications and corrections on the questionnaire and interview guides. A reliability coefficient of 0.72 was calculated using test-retest method for reliability.

Descriptive statistics such as percent and frequencies were used to determine the extent of generation and the degree of acceptability of herbal medicine R&D outputs from the various research bodies and herbal medicine consumers respectively, at 5% and 10% confidence levels. The factors that influenced the generation of herbal medicine R&D outputs which were identified as researchers age(X₁), years of experience (X ₂),qualifications(X₃),availability of training X₄(in house and abroad) , funding of R&D (X₅),availability of R&D infrastructure (X₆), freedom in selecting R&D projects (X₇),motivation from management (X₈),collaboration with other researchers(X₉)and granting of patent rights by the university or research institute (X₁₀).were analyzed using inferential statistics such as correlation technique and multiple regression analysis. The later was carried out by modeling the performance of these explanatory variables and we regressed the variables against the dependent variable; herbal medicine R&D outputs (Q). Estimation was done by Ordinary Least Square (OLS) using E-view software.

RESULTS AND DISCUSSION:

Two hundred and fourty questionnaires were completed, and the overall response rate obtained was approximately 74%. Majority 172(71.67%) of the respondents were males while 68(28.33%) were females. Most respondents, (49.2%) were in the age bracket of 40-49 years, followed by those who were 50-59 years of age (17.5%). The percentages of respondents who were in other age brackets were very low. Majority (38%) had Masters of Science degrees, followed by 35% with Ph.D. degrees. Only few, 20% and 6% had Bachelor’s degrees and Higher National Diploma (HND) certificates respectively. The qualifications of herbal medicine R&D scientists were high with majority of the herbal medicine scientists having Masters and Doctor of Philosophy degrees. This trend was expected because herbal medicine R&D has a high scientific R&D content which requires very highly knowledgeable and qualified personnel who not only handle basic and applied research but also manipulate sophisticated processes and equipments that are routinely used in carrying out research. Since knowledge is often tacit and is stored in the heads of experienced employees, it is essential for firms to employ competent workers for the various jobs. The success of a technology depends on its user’s ability to apply it. Hence, the employee’s individual characteristics of qualification, experience and performance have to correspond with the demands of the enterprise ¹². Majority, 162(67.5%) of the R&D researchers had on the job experience of between 15-29 years; while 60(25%) of them had less than 14years of experience on the job. Only a handful of the researchers 18(7.5%), had above 30 years on the job experience. The demographic data are given in details in Table 1.

Table 1: Demographics of herbal medicine research scientists who participated in the study

Parameters

No. of Respondents

Percentage

Gender

Male

Female

Total

172

240

71.67

28.33

100

Age group (year)

20-29

30-39

40-49

50-59

Above to

Total

118

240

13.8

7.1

49.2

17.5

12.5

100

Educational Qualification

Years of experience

HND

B. Pharm/ BSc

MSc/ M.Phil

Ph.D.

Total

00-14

15-29

>30

Total

240

162

240

6.25

20.42

37.92

35.42

100

67.5

7.5

100

Source: Field survey, 2010.

In Table 2, the total herbal medicines R&D outputs generated from all the universities surveyed were 839. Out of which Obafemi Awolowo University had the highest (19.31%), followed by Universities of Lagos (15.73%), Nigeria (14.3%), Amadu Bello (13.11%), Benin (8.11%),Maiduguri, (6.32%), Jos (6.08%), Ibadan (5.24%), Port-Harcourt(1.43%). Furthermore, Obafemi Awolowo University had the highest percentage of newly developed products (15.71%), followed by Universities of Nigeria (15.33%), Ahmadu Bello (13.79%), Lagos (12.64%), Jos (11.88%), Benin, (8.43%), Maduguri, (5.36%), Port-Harcourt, (4.59%), Olabisi Onabanjo (3.45%) Ibadan, (3.83%), Madonna (2.29%), Niger Delta (1.53%) and Igbinedion (1.15%). Manufacturing Pharmaceutical firms/herbal medicine producers had to their credit a total number of 1220 herbal medicines research outputs, out of which 88.52% were developed as new products. The outstanding performances of certain universities such as Obafemi Awolowo, Lagos, Nigeria, Ahmadu Bello and Benin in terms of research outputs and development of new products could be ascribed to the age of establishment of their various faculties of pharmacy. These faculties have been in existence since about four decades ago. The low performance of the latter groups of universities in Table 2 could be due to the fact that some of the facilities required for active R&D are not yet in place. In such case, highly qualified personnel may abound but the requisite tools or equipment necessary for undertaking research works in herbal medicine R&D could be in short supply.

The socio-demographic characteristics of herbal medicines consumers showed that out of the 300 respondents, majority (64%) were females while the remaining (36%) were males. About 14% and 20% were in the age ranges of 21-30years and 31-40years respectively. Majority (25%) of them were in the age range of 41-50 years while about 23% fell between the age brackets of 51-60 years. Only about 19% were above the age of 60years. Most (56%) of the herbal medicine consumers were married while only (11%) were single. In addition, 25% were divorced from previous marriages while 7% were separated. Majority (42%) live in the rural areas while 39% lived in sub-rural areas. Only 19% lived in the urban centres. About 60% of the respondents were Moslems while 28% were Christians. Only 12% were traditionalists. Most (44%) of the respondents were Yoruba, while 34% were Ibos. Only 23% were Hausas. Majorities (54%) of the respondents were farmers and about 19% were traders. Only 8% and about 19% were either in the managerial cadre or professionals in various fields, respectively. About 46% of the herbal medicine consumers earn a monthly income of above $330 while about (7%) earn the least monthly income of between $7- $60. The rest (46%) earn about $67 to $330 monthly. The respondents had different educational backgrounds. About 60% had post secondary education, 8% primary school, 10% secondary school and 23% had non-formal education. The assessment of the level of acceptability for herbal medicines by their consumers based on hitherto listed criteria is presented in details in Table 3. Three hundred herbal medicine consumers rated the Level of acceptability for herbal medicines on a 5-point Likert Scale based on the mean scores obtained for each of the following variables namely, safety (3.56), affordability (2.85), packaging (2.73), side effects (2.57), efficacy (2.34) and availability (2.15). Herbal medicine consumers perceived herbal drugs to be safer, easily affordable, readily available, relatively efficacious and devoid of side effects. In addition, most manufacturers of herbal medicines usually make bogus claims on the therapeutic capabilities or competences of herbal preparations with respect to the range of disease conditions that they could handle. Nevertheless, past studies revealed that many patients who had used herbal medicines with good therapeutic outcomes later discovered that the benefits were actually due to the presence of other orthodox medicines that are adulterants in the herbal preparations hitherto taken^{13, 14}. The limited knowledge of most herbal medicine consumers on the pharmacology of drugs as it relates to safety, efficacy, drug-drug interactions among others, could pose a great challenge in evaluating drug performance. It has been argued elsewhere that even conventional healthcare providers in Nigeria have shallow knowledge of the pharmacology of most herbal medicines available in the country ¹⁵. In all, most herbal medicine consumers reported that herbal medicines were free of side-effects. This finding corroborates the earlier assertion that herbal medicines are not toxic in nature and are products of natural origin which is close to the culture of the people ^{4, 10}.However, on oral interview, some herbal medicine consumers agreed that they actually took herbal medicines alongside orthodox medicines. This could also pose a great challenge in assessing the performance of herbal medicines.

Table 2: Herbal medicines R&D outputs generated by various research bodies

Institutions

R&D Outputs

No of products developed

University Of Maiduguri

University Of Ibadan

University Of Port-Harcourt University Of Benin

University Of Jos

University Of Nigeria NsukkaObafemi Awolowo University

Madonna University

Igbinedion University

Olabisi Onabanjo University

Ahmadu Bello University

Niger/Delta University

University of Lagos

Total

Research Institutes

National Institutes for pharmaceutical Research & Development (NIPRD)

Nigerian Natural Medicine and Development Agency (NNMDA)

Pax herbal Clinic Ewu

Total

Manufacturing Pharmaceutical Firms/Herbal medicine producers

53 (6.32%)

44 (5.24%)

36 (4.29%)

68 (8.11%)

51 (6.08%)

120 (14.30%)

162 (19.31%)

18 (2.15%)

12 (1.43%)

14 (1.67%)

110(13.11%)

19 (2.26%)

132 (15.73%)

839

28 (31.46%)

43 (48.31%)

18(20.22%)

1220(100%)

14(5.36%)

10(3.83%)

12(4.59%)

22(8.43%)

31(11.88%)

40(15.33%)

41(15.17%)

6(2.29%)

3(1.15%)

9(3.45%)

36(13.79%)

4(1.53%)

33(12.64%)

261

11(24.44%)

8(40%)

16(35.56%)

1080(88.52%)

Source: Field Survey, 2010.

Table 3: Respondents’ assessment of the level of acceptability of herbal Medicines R & D outputs in Nigeria

Variables	Very low 1	Low 2	Fairly high 3	High 4	Very high 5	Mean
Affordability	89	47	44	59	61	2.85
Packaging	100	40	41	49	64	2.73
Availability	109	28	31	37	48	2.15
Efficacy	121	27	32	44	51	2.34
Side Effect	191	78	41	36	34	2.57
Safety	37	39	53	62	109	3.57
Source: Field Survey, 2010.

Table 4: Step - Wise Correlation Matrix of Variables of Output of Herbal Medicine R&D and Other Independent Variables

Variables

X₁

X₂

X₃

X₄

X₅

X₆

X₇

X₈

X₉

X₁₀

X₁

X₂

X₃

X₄

X₅

X₆

X₇

X₈

X₉

X₁₀

1.000

0.421**

0.594**

0.429**

0.493*

0.486*

0.166

0.356**

-0.279*

0.535*

0.290*

1.000

0.688**

-0.141

0.327**

0.239*

0.187

0.265*

0.235*

-0.227

-0.085

1.000

-0.157

0.375**

-0.076

0.254*

0.363**

0.249*

0.325**

0.258

1.000

-0190

0.617**

0.240

0.386**

-0.217

0.223

0.553**

1.000

-0.037

0.257**

0.167

0.162

0.463*

0.261

1.000

-0.131

0.404**

-0.252*

0.214

0.389

1.000

0.134

0.020

-0.206

-0.209

1.000

0.400**

0.252

0.257

1.000

-0.146

0.250

1.000

0.510**

1.000

** Correlation is significant at the 0.01 level (2-tailed)

* Correlation is significant at the 0.05 level (2-tailed) Source: Field Survey, 2010

Evaluation of the influence of herbal medicines researchers age, years of experience, qualifications, availability of training (in house and abroad), funding of R&D, availability of R&D infrastructure, freedom in selecting R&D projects, motivation from management, collaboration with other researchers and granting of patent rights by the university or research institute on herbal medicines R&D outputs showed that there were significant correlations between R&D outputs and age of the scientists (r=0.421),experience of the scientists(r=0.594),R&D funding (r=0.429), qualifications of the scientists(r=0.421), availability of R&D facility(0.486) and freedom in selecting R&D projects(r=0.356) Table 4. Regression analysis of herbal medicine R&D output (Q ) on the factors that influence their generation revealed that experience of scientists ( β₁=1.800), freedom in selecting R&D projects(β₂=0.015) and training of scientists(β₃=1.74) contributed significantly to research outputs at 5% and 10% levels of probability (Table 5). The only factor that negatively influenced the generation of herbal medicine outputs was variable X₈ (collaboration with other researchers). The variable collaboration with other research associations had a coefficient of -0.03(Table 5). This coefficient was not significant at both 5% and 10% probabilities. This implies that as herbal medicine researchers collaborate with each other or other organizations, research output decreases by 0.03 units. Collaboration is expected to increase research productivity ¹⁶. However, the opposite was the case in this study. One of the likely reasons for this deviation is that the operational environment for herbal medicine researchers may not encourage enough interaction or collaborative efforts among the researchers. Therefore caution should be exercised in forming research collaboration especially among herbal medicine scientists.

The following regression results for herbal medicine R&D outputs Q were obtained based on a priori expectation, R², standard error regression estimates and the F-values of the overall equations.

Table 5: Results of the regression analysis of factors influencing the generation of herbal medicines R&D outputs

(Dependent variable is herbal medicine (R&D) output.

Explanatory variables	Coefficients	t-statistics
X₁	1.60	1.512**
X₂	1.80	3.327**
X₃	1.32	5.635
X₄	0.213	1.688
X₅	0.52	1.555
X₆ X₇	0.136 0.015*	1.646 0.342**
X₈	-0.03	1.042
X₉	1.74	1.435*
X₁₀	0.457	0.141
Other statistics R²=0.783; Adjusted R²=0.738; DW=1.2; Standard Error=0.1878; F=17.649

Source: Field Survey, 2010. *Significant at 5%; **Significant at 10%.

The R² is the conventional measure of goodness of fit; DW is the conventional Durbin Watson statistics that tests for the presence of first-order auto-correlation among error terms. While F, is the conventional F-statistics that test for the joint significance of all parameters in the estimated model. Statistical property of the model is very good and virtually all a priori expectations were met. Therefore valid inferences could be drawn from the results.

This work is limited by the time frame that was used to carry out the study-2007 to 2010 even though the six geopolitical zones in the country were covered. Longer period may give room for wider coverage with comprehensive results that could be more illuminating. This does not in any way diminish the quality of the results obtained and it’s far reaching effects.

CONCLUSION:

The study concluded that the generation of herbal medicines research and development outputs in Nigeria is enormous. However, care must be taken in accepting completely the results on the level of acceptability of herbal medicines by herbal medicine consumers because most of them confessed taking herbal medicines with orthodox medicines during the oral interview section. This made it difficult to state categorically which type of medicine was responsible for whatever action.

ACKNOWLEDGEMENTS:

We remain eternally grateful to the Directors and Chief Executive Officers of National Institute for Pharmaceutical Research and Development (NIPRD) and Nigerian Natural Medicine and Development Agency (NNMDA), Professor Okogun and Mr. Sam. Etatuvie respectively, who made it possible for us to administer questionnaire to and conduct personal oral interview with core herbal medicine R&D researchers in the above-mentioned institutes. We also thank Rev. Father Anslem Adodo, Head, Pax Herbal Clinic, Ewu for organizing his fellow Monks who are herbal medicine researchers in the St. Benedicts Monastery, to fill questionnaires and answer relevant follow up questions in the interview schedule.

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Received on 17.03.2011 Modified on 20.10.2012

Research J. Pharm. and Tech. 6(3): March 2013; Page 232-237

No. of Respondents

Percentage

1. Elujoba AA. Pharmacognostical Standardization of Herbal Medicine: Standardization and Utilization of Herbal medicine: Challenges of the 21st Century. Proceedings of an International Workshop. Department of Pharmacognosy, University of Ibadan Nov. 22-24. 1998: pp. 30-43.

4. Moody JO. Traditional Medicine. Paper Delivered at the Mandatory Continuing Professional Development (MCPD) Programme, Module V, Faculty Pharmacy, University of Ibadan, Nov. 21-22. 2008: pp. 1-6.

1. Elujoba AA. Pharmacognostical Standardization of Herbal Medicine: Standardization and Utilization of Herbal medicine: Challenges of the 21^st Century. Proceedings of an International Workshop. Department of Pharmacognosy, University of Ibadan Nov. 22-24. 1998: pp. 30-43.